Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.61 (caspase-8)
 6,833 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bronchial airway epithelial cells (BAEpC) are among the first cells to encounter M. tuberculosis following airborne infection. However, the response of BAEpC to M. tuberculosis infection has been little studied. This study investigates the response of a human BAEpC cell line (BEAS-2B) to infection with Mycobacterium bovis Bacille Calmette Guerin (BCG). Cultured human BEAS-2B cells were experimentally infected with BCG. Uninfected BEAS-2B cultures were included as controls. Following infection, BEAS-2B cells were evaluated by various methods at various time points up to 3 days. Cell proliferation was evaluated by cellular bioreduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Distribution of cells along the cell cycle was evaluated by FACS analysis of cellular DNA. Apoptotic cells were identified by cell death ELISA and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling method. Eighty-four apoptosis-relevant genes were screened by PCR gene microarray. Translation of Fas, Fas ligand (Fas-L), and Fas-associated death domain (FADD) were evaluated quantitatively by real-time PCR. Expression of Fas and FADD proteins was evaluated by immunofluorescence and Western blot. Activity of caspase-3 and caspase-8 was evaluated by colorimetric assay of their enzymatic activity. BCG infection of BEAS-2B cells inhibits proliferation, induces cell cycle arrest at the G(0)/G(1) phase, causes apoptosis, modulates transcription of multiple apoptosis-relevant genes, promotes translation of Fas, Fas-L, and FADD, upregulates expression of Fas and FADD proteins, and increases activity of caspase-3 and caspase-8. Infection with BCG does not cause any significant change in the secretion of TGF-beta. The roles of Fas and FADD as mediators of BCG-induced apoptosis in BEAS-2B cells were tested by partial blockade of Fas and FADD expression with silencing RNA. Partial blockade of Fas or FADD expression results in a decreased apoptotic response to BCG infection. In conclusion, BCG induces cell cycle arrest and apoptosis in BEAS-2B cells. BCG induced apoptosis of BEAS-2B cells via the Fas death receptor pathway.
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PMID:Induction of cell cycle arrest and apoptosis by BCG infection in cultured human bronchial airway epithelial cells. 1752 97

To clarify the protective role of transforming growth factor (TGF)-beta for the intestinal epithelial injury in vivo, the effect of antibodies against TGF-beta on epithelial destruction and apoptosis was assessed in dextran sulfate sodium (DSS)-induced colitis by histological analysis of colonic sections, account of apoptotic epithelial cells. To evaluate the pathways of epithelial apoptosis, we analyzed the activities of caspases, the level of Fas and cellular FLICE-inhibitory protein (cFLIP) expression in epithelial cells. Apoptotic epithelial cells were increased prior to the onset of ulceration in DSS-induced colitis, and the neutralization of TGF-beta exacerbated epithelial apoptosis and histological damage score. The up-regulation of caspase-8 activity and Fas expression and reduced cFLIP expression were observed in intestinal epithelial cells from anti-TGF-beta antibody-treated mice. The present study revealed that suppression of TGF-beta deteriorated epithelial apoptosis, and the increase of apoptotic epithelial cells may amplify the inflammation in gut mucosa.
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PMID:Blockade of TGF-beta accelerates mucosal destruction through epithelial cell apoptosis. 1756 May 53

Androgen withdrawal induces the regression of human prostate cancers, but such cancers eventually become androgen-independent and metastasize. Thus, deciphering the mechanism of androgen withdrawal-induced apoptosis is critical to designing new therapies for prostate cancer. Previously, we showed that in the rat, castration-induced apoptosis is accompanied by a reduction in the expression of the apical caspase inhibitor FLICE-like inhibitory protein (FLIP). To test the functional role of FLIP in inhibiting prostate epithelial cell apoptosis, we employed the rat prostate epithelial cell line NRP-152, which differentiates to a secretory phenotype in a low-mitogen medium and then undergoes apoptosis following the addition of transforming growth factor beta1 (TGFbeta1), mimicking androgen withdrawal-induced apoptosis. FLIP levels decline with TGFbeta1 treatment, suggesting that apoptosis is mediated by caspase-8 and indeed the caspase inhibitor crmA blocks TGFbeta1-induced apoptosis. Small interfering RNA-mediated knockdown of FLIP recapitulates and enhances TGFbeta1-induced cell death. NRP-152 cells stably transfected with constitutively expressed FLIP were refractory to TGFbeta1-induced apoptosis. TGFbeta1-induced caspase-3 activity is proportional to the level of cell death and inversely proportional to the level of FLIP expression in various clones. Moreover, neither caspase-3 nor PARP is cleaved in clones expressing high levels of FLIP. Furthermore, insulin, which inhibits differentiation, increases FLIP and inhibits TGFbeta-induced death in a FLIP-dependent manner. Although neither Fas-Fc, sTNFRII-Fc, nor DR5-Fc blocked TGFbeta1-induced cell death, there is a significant increase in tumor necrosis factor mRNA following TGFbeta stimulation, suggesting both an unexpected role for tumor necrosis factor in this model system and the possibility that FLIP blocks another unknown caspase-dependent mediator of apoptosis.
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PMID:FLICE-like inhibitory protein blocks transforming growth factor beta 1-induced caspase activation and apoptosis in prostate epithelial cells. 1831 84

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by dysregulation of cytokines, apoptosis, and B- and T-cell functions. The tolerogenic peptide, hCDR1 (Edratide), ameliorated the clinical manifestations of murine lupus via down-regulation of pro-inflammatory cytokines and apoptosis, up-regulation of the immunosuppressive cytokine TGF-beta, and the induction of regulatory T-cells. In the present study, gene expression was determined in peripheral blood mononuclear cells of 9 lupus patients that were treated for 26 weeks with either hCDR1 (five patients), or placebo (four patients). Disease activity was assessed by SLEDAI-2K and the BILAG scores. Treatment with hCDR1 significantly down-regulated the mRNA expression of the pathogenic cytokines IL-1beta, TNF-alpha, IFN-gamma, and IL-10, of BLyS (B-lymphocyte stimulator) and of the pro-apoptotic molecules caspase-3 and caspase-8. In contrast, the treatment up-regulated in vivo gene expression of both TGF-beta and FoxP3. Furthermore, hCDR1 treatment resulted in a significant decrease in SLEDAI-2K (from 8.0+/-2.45 to 4.4+/-1.67; P=0.02) and BILAG (from 8.2+/-2.7 to 3.6+/-2.9; P=0.03) scores. Thus, the tolerogenic peptide hCDR1, immunomodulates, in vivo, the expression of genes that play a role in SLE, consequently restoring the global immune dysregulation of lupus patients. Hence, hCDR1 has a potential role as a novel disease-specific treatment for lupus patients.
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PMID:Treatment of lupus patients with a tolerogenic peptide, hCDR1 (Edratide): immunomodulation of gene expression. 1934 2

Transforming growth factor-beta1 (TGF-beta1) is the most abundant TGF-beta isoform detected in bone and is an important functional modulator of osteoclasts. TGF-beta1 can induce osteoclast apoptosis; however, the apoptotic pathways involved in this process are not known. We show here that human osteoclasts express both type-I and type-II TGF-beta receptors. In the absence of survival factors, TGF-beta1 (1 ng/ml) induced osteoclast apoptosis. The expression of activated caspase-9, but not that of caspase-8, was increased by TGF-beta1 stimulation, and the rate of TGF-beta1-induced apoptosis was significantly lower in the presence of a caspase-9 inhibitor. To study further the mechanisms involved in TGF-beta1-induced osteoclast apoptosis, we investigated TGF-beta1 signaling, which primarily involves the Smad pathway, but also other pathways that may interfere with intracellular modulators of apoptosis, such as mitogen-activated protein (MAP) kinases and Bcl2 family members. We show here that early events consisted of a trend toward increased expression of extracellular signal-regulated kinase (ERK), and then TGF-beta1 significantly induced the activation of p38 and Smad2 in a time-dependent manner. These signaling cascades may activate the intrinsic apoptosis pathway, which involves Bim, the expression of which was increased in the presence of TGF-beta1. Furthermore, the rate of TGF-beta1-induced osteoclast apoptosis was lower when Bim expression was suppressed, and inhibiting the Smad pathway abolished Bim up-regulation following TGF-beta stimulation. This could correspond to a regulatory mechanism involved in the inhibition of osteoclast activity by TGF-beta1.
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PMID:Transforming growth factor-beta1 (TGF-beta1) induces human osteoclast apoptosis by up-regulating Bim. 1957 21

Cyclosporine is a potent immunomodulator and has a beneficial effect in the treatment of ulcerative colitis (UC). We analyzed the mechanism of the effects of cyclosporine on the regulation of epithelial apoptosis via TGF-beta-related signaling, because the balance between the apoptosis and regeneration of epithelial cells seems to be a key factor to maintain the intestinal homeostasis. For this purpose, colitis was induced by treatment of 4% dextran sulfate sodium (DSS), and the effect of treatment with cyclosporine and anti-TGF-beta antibody was assessed. Treatment with cyclosporine ameliorated body weight loss, mucosal destruction, and epithelial apoptosis in DSS-induced colitis. Cyclosporine was shown to upregulate the expression of TGF-beta in the colonic tissue, enhance the expression of p-Smad2 and cFLIP in epithelial cells, and inhibit caspase-8 activity but not caspase-1 or -9. Upregulation of cFLIP in the colonic epithelial cells, amelioration of body weight loss, and mucosal destruction by cyclosporine were attenuated by anti-TGF-beta antibody treatment. These results indicated that cyclosporine could have a protective role against epithelial apoptosis associated with upregulation of TGF-beta-related signaling.
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PMID:Cyclosporine regulates intestinal epithelial apoptosis via TGF-beta-related signaling. 1960 30

Inhibitors of catalase (such as ascorbate, methyldopa, salicylic acid and neutralizing antibodies) synergize with modulators of nitric oxide (NO) metabolism (such as arginine, arginase inhibitor, NO synthase-inducing interferons and NO dioxygenase inhibitors) in the singlet oxygen-mediated inactivation of tumor cell protective catalase. This is followed by reactive oxygen species (ROS)-dependent apoptosis induction. TGF-beta, NADPH oxidase-1, NO synthase, dual oxidase-1 and caspase-9 are characterized as essential catalysts in this process. The FAS receptor and caspase-8 are required for amplification of ROS signaling triggered by individual compounds, but are dispensable when the synergistic effect is established. Our findings explain the antitumor effects of catalase inhibitors and of compounds that target NO metabolism, as well as their synergy. These data may have an impact on epidemiological studies related to secondary plant compounds and open new perspectives for the establishment of novel antitumor drugs and for the improvement of established chemotherapeutics.
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PMID:Synergistic effects between catalase inhibitors and modulators of nitric oxide metabolism on tumor cell apoptosis. 2527 27

Hydrogen peroxide (H2O2) is both an exogenous and endogenous cytotoxic agent that can reliably induce apoptosis in numerous cell types for studies on apoptosis signaling pathways. However, little is known of these apoptotic processes in myocardial cells of chicken, a species prone to progressive heart failure. Sequencing of mRNA transcripts (RNA-Seq) allows for the identification of differentially expressed genes under various physiological and pathological conditions to elucidate the molecular pathways involved, including cellular responses to exogenous and endogenous toxins. We used RNA-seq to examine genes differentially expressed during H2O2-induced apoptosis in primary cultures of embryonic chicken cardiomyocytes. Following control or H2O2 treatment, RNA was extracted and sequencing performed to identify novel transcripts up- or downregulated in the H2O2 treatment group and construct protein-protein interaction networks. Of the 19,268 known and 2,160 novel transcripts identified in both control and H2O2 treatment groups, 4,650 showed significant differential expression. Among them, 55.63% were upregulated and 44.37% downregulated. Initiation of apoptosis by H2O2 was associated with upregulation of caspase-8, caspase-9, and caspase-3, and downregulation of anti-apoptotic genes API5 and TRIA1. Many other differentially expressed genes were associated with metabolic pathways (including 'Fatty acid metabolism', 'Alanine, aspartate, and glutamate metabolism', and 'Biosynthesis of unsaturated fatty acids') and cell signaling pathways (including 'PPAR signaling pathway', 'Adipocytokine signaling pathway', 'TGF-beta signaling pathway', 'MAPK signaling pathway', and 'p53 signaling pathway'). In chicken cardiomyocytes, H2O2 alters the expression of numerous genes linked to cell signaling and metabolism as well as genes directly associated with apoptosis. In particular, H2O2 also affects the biosynthesis and processing of proteins and unsaturated fatty acids. These results highlight the value of RNA-seq for revealing unexpected molecular contributors to oxidative stress responses, thereby identifying novel potential therapeutic targets.
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PMID:Differential Gene Expression Patterns in Chicken Cardiomyocytes during Hydrogen Peroxide-Induced Apoptosis. 2680 97


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